Convective cushion with positive coefficient of resistance heating mode

A mattress pad comprising:

• a plenum defined by a laterally extending bottom surface and a laterally extending air permeable top surface secured around a perimeter extending transversely therebetween, the plenum containing an air flow space, an air flow structure formed of fabric material and having an opening at one end disposed in the air flow space, said air flow structure spacing the top surface from the bottom surface, said top surface adapted for convective air flow delivered from said air flow structure over substantially the entire top surface responsive to a flow of air blown laterally into said plenum, said top surface being sufficiently impervious to air to retain greater air pressure within the air flow space, said air flow structure guiding a substantial portion of said flow of air to maintain a venting air flow passing in a coplanar direction laterally between said top and bottom surfaces to be directed laterally outward through said plenum perimeter, a portion of the flow of air venting through said top surface;
• an air duct with one end sized to be received into the opening and a second end extending outside the plenum;
• a power unit housing a blower in fluid communication with a heating module and connected to the second end of the air duct;
• a controller unit in communication with the blower and the heating element;
• and
• wherein the heating module comprises a positive temperature coefficient type heating element in conduction with a heat exchanger, whereby a user resting atop the pad is able to control the blower and heating module to deliver air of a desired temperature and quantity to the pad and to said air flow structure to deliver said air of desired temperature and quantity to said top surface to produce the convective air flow over substantially all of the top surface.